When Kath collaborated with singer Alice Glass on some songs in spring 2005, Crystal Castles' lineup was complete.

One of the songs the pair recorded, "Alice Practice," was something of an accident: it was intended to be a demo of Glass testing out a microphone, but its presence on My Space piqued record labels' interest.

For 2012's more streamlined III, the duo decamped to Warsaw, where they recorded direct to tape, eschewing any computer-assisted recording.

Glass left the project in October 2014 to pursue a solo career; in April 2015, Kath resurfaced with a new Crystal Castles track, "Frail," which featured new vocalist Edith Frances.